The venerable gear pump is so strongly associated with hydraulics that perhaps only cylinders are more prominent in this industry. There is good reason for the popularity of the hydraulic gear pump; they are simple, inexpensive, durable and interminable. I’ve seen them made from about five pieces if you don’t count seals and bolts, and […]
The importance of pressure compensation
When I was a Padawan Learner of hydraulics, I found the concept of pressure compensation to be difficult to understand. Part of my difficultly was also a result of my difficulty understanding pressure drop, which is intimately related to pressure compensation. For general pressure compensation, it describes a component that varies an orifice to maintain […]
Beta ratio: Identifying the quality of a hydraulic filter element
I wrote about the ISO 4406 cleanliness code in my last two blogs here and here, and today I’d like to take it a bit further and discuss beta ratios. Beta ratios are important to help us identify the quality of a hydraulic filter element. If using the ISO Code to help identify and specify […]
Why the ISO code matters
Earlier this month, I explained the meaning behind the ISO 4406 contamination code, so now I’m explaining why it matters, and how you can apply it to your application. The code describes the quantity of 4-, 6- and 14 -μm particles in a milliliter of hydraulic fluid—because these particle sizes are considered the most damaging […]
Understanding ISO 4406
The most critical quality of hydraulic fluid you should consider is that of cleanliness. We refer to the size and quantity of particle contamination when discussing cleanliness, and so that we are all on the same page, standards were created for measuring and expressing this quality. Although the standard for oil cleanliness has changed over […]
Accumulator fundamentals … without the math
I’m going to attempt the impossible: I am going to explain the fundamentals of hydro-pneumatic accumulators without using any mathematics. I will use some numbers where needed, but the unfortunate reality is that the proper application of accumulators does require the manipulation of equations. Accumulators are a versatile and valuable tool, but because of the […]
The challenges of mobile reservoir design
Hydraulic oil spends most of its time in the reservoir, and as such, various tank design criteria provide benefits for the hydraulic system as a whole. When designing the optimum hydraulic reservoir, most of the considerations are in keeping the oil clean and cool. Reservoirs in industrial applications are spoiled by the extra space and […]
Comparing blood pressure to fluid power pressure
Blood pressure is an interesting measurement of biological health. Most of us use the term as if it has no relation at all to fluid mechanics, and we might as well call it floxcore gleblu or some other randomly generated name (actual randomly generated word). In pneumatics, 150 psi is considered very high, and most […]
5 things your father never told you about mobile hydraulic fluids
Josh Cosford • Contributing Editor Dad was a lot of things, but he was no hydraulic expert. However, that doesn’t mean he (and everyone else) didn’t have an opinion on hydraulic oil. The problem with opinions is that they come from persons with enough knowledge that people listen—but enough knowledge to be potentially dangerous with […]
Similarities between hydraulic and electric symbols
Earlier, I mentioned how electric and hydraulic actuators are similar in execution and principle, and in this blog post I’d like to finish off the mini-series on the similarities between hydraulic and electric symbols. The most obvious similarity is the conductor,which is a hose in hydraulics or a wire in electrics. The physical manifestation can vary—such […]
